1 /* 2 * @(#)FP.h 5.1 (Berkeley) 11/03/86 3 * 4 * General definitions of the floating point stuff on Power 6/32. 5 * The floating point format definition is: 6 * 7 * S (exp-128) 8 * (-1) * 2 * F 9 * 10 * Where exp is the exponent field and F is the binary 11 * mantissa following it, including the hidden bit. 12 * The hidden bit actually is 1/2, so F is known to 13 * satisfy the range: 14 * 1/2 <= F < 1 15 */ 16 17 typedef struct { 18 unsigned sign:1; 19 unsigned exponent:8; 20 unsigned mantissa:23; 21 } sp_format; 22 23 typedef struct { 24 unsigned sign:1; 25 unsigned exponent:8; 26 unsigned mantissa:23; 27 unsigned mantissa_lst; 28 } dp_format; 29 30 #define EXP_BIAS 128 /* Exponent bias */ 31 #define SIGN_BIT 0x80000000 /* S bit mask */ 32